no chart, best time is when night temps stay above 65 degrees, it will mostly mean day temps will be in the high 80's to mid 90's. every part of the world has different temp depending on geographic location. I normally dont graft in Oct, but grafted few a week ago citing heatwave in So Cal, I got takes already but its a low percentage.
besides the night temps, most important thing is to have the rootstock actively pushing.